example.cpp

#include "gut.h"
#include <algorithm>
#include <stdexcept>
#include <vector>

class RecentlyUsedList {
    std::vector<std::string> items_;
public:
    bool empty() const { return items_.empty(); }
    size_t size() const { return items_.size(); }
    std::string operator[](size_t index) const {
        if (index >= size())
            throw std::out_of_range("invalid subscript");
        return items_[size() - index - 1];
    }
    void insert(const std::string& item) {
        auto found = std::find(begin(items_), end(items_), item);
        if (found != items_.end())
            items_.erase(found);
        items_.push_back(item);
    }
};

GUT_ENABLE_COLORINCONSOLE

TEST("Initial list is empty") {
    RecentlyUsedList anEmptyList;

    CHECK(anEmptyList.empty());
    CHECK(anEmptyList.size() == 0);
}

TEST("Insertion to empty list is retained") {
    RecentlyUsedList aListWithOneElement;
    aListWithOneElement.insert("one");

    CHECK(!aListWithOneElement.empty());
    CHECK(aListWithOneElement.size() == 1);
    CHECK(aListWithOneElement[0] == "one");
}

TEST("Distinct insertions are retained in stack order") {
    RecentlyUsedList aListWithManyElements;
    aListWithManyElements.insert("one");
    aListWithManyElements.insert("two");
    aListWithManyElements.insert("three");

    CHECK(!aListWithManyElements.empty());
    CHECK(aListWithManyElements.size() == 3);
    CHECK(aListWithManyElements[0] == "three");
    REQUIRE(aListWithManyElements[1] == "two");
    CHECK(aListWithManyElements[2] == "one");
}

TEST("Duplicate insertions are moved to the front but not inserted") {
    RecentlyUsedList aListWithDuplicatedElements;
    aListWithDuplicatedElements.insert("one");
    aListWithDuplicatedElements.insert("two");
    aListWithDuplicatedElements.insert("three");
    aListWithDuplicatedElements.insert("two");

    CHECK(!aListWithDuplicatedElements.empty());
    CHECK(aListWithDuplicatedElements.size() == 3);
    CHECK(aListWithDuplicatedElements[0] == "two");
    CHECK(aListWithDuplicatedElements[1] == "three");
    CHECK(aListWithDuplicatedElements[2] == "one");
}

TEST("Out of range indexing throws exception") {
    RecentlyUsedList aListWithOneElement;
    aListWithOneElement.insert("one");

    THROWS(aListWithOneElement[1], std::out_of_range);
}